In this paper, we consider the multi depot heterogeneous vehicle routing problem with time windows in which vehicles may be replenished along their trips. Using the modeling technique in a new-generation solver, we construct a novel formulation considering a rich series of constraint conditions and objective functions. Computation results are tested on an example comes from the real-world application and some cases obtained from the benchmark problems. The results show the good performance of local search method in the efficiency of replenishment system and generalization ability. The variants can be used to almost all kinds of vehicle routing problems, without much modification, demonstrating its possibility of practical use.
With the intensification of market competition, the competition form of firms is evolving from the competition among firms to the competition among supply chains. This paper considers a market with two competing supply chains consisting of one supplier and one manufacturer. The two supply chains compete on products’ quantities and research and development (R & D) level when the two manufacturers conduct technological innovation. This paper analyses the supply chain competition in three scenarios: two decentralized supply chains (DD), one decentralized supply chain and one centralized supply chain (DC) and two centralized supply chains (CC). The results indicate that the production quantity, the R & D level and the total profit of the integrated supply chain in DC scenario are the largest, CC scenario comes second, those of the DD scenario come third and those of the decentralized supply chain in DC scenario are the smallest. CC strategy is the supply chain system’s Nash equilibrium, which is good for the both supply chains, and there is no prisoner & apos; s dilemma.
This study develops an effective method to measure value chain performance and rank them based on qualitative criteria and to determine the ranking order of the various forms of performance under study. This approach integrates the advantage of grey systems theory and TOPSIS to evaluate and rank value chain performance. Grey-TOPSIS approach has been applied to measure and rank the value chain performance of various firms. The results indicate that the proposed model is useful to facilitate multi-criteria decision-making (MCDM) problem under the environment of uncertainty and vagueness. The model also provides an appropriate ranking order based on the available alternatives. The Grey-TOPSIS approach that will be useful to the managers to use for solving the similar type of decision-making problems in their firms in the future has been discussed. Even though, the problem of choosing a suitable performance option is often addressed in practice and research, very few studies are available in the literature of Grey-TOPSIS decision models. Also, Grey-TOPSIS model application in the tea processing firms is non-existence hence this study is the very first to apply this model in evaluating value chain performance in the tea processing firms.
Exchange rates always affect the prices of the imports and export of products and services in which countries are trading with other parts of the world. Therefore, exchange rate calculation is one of the essential issues for making appropriate policies. This research investigates the determinants of trade, i.e. import, export, industrial growth, consumption level and oil prices fluctuation, which bring changes in exchange rate and their influence eventually on balance of payments. Data of defined variables was collected on yearly basis for China and USA for thirty one years. By applying cointegration, it is estimated that there existed a long run relationship in both countries. USA and China had significant and correct signs on the short run dynamic and some of the factors did not. Exchange rate did not granger cause balance of payment and balance of payment did not granger cause exchange rate. In conclusion, we found that determinants of balance of trade could affect the exchange rates, also, these rates had considerable effect (positive or negative) on balance of payments. In this twofold study, we found relationship of exchange rate with selected determinants of trade, and also examined their bilateral effect, and then made contrast of both countries.
The safety of civil aviation will be more secured if the errors in all the facets can be reduced. Like the other industrial sectors, human resource is one of the most complex and sensitive resources for the civil aviation. The error of human resources can cause fatal disasters. In these days, a good volume of researches have been conducted on the disaster of civil aviation. The researchers have identified the causes of the civil aviation disasters from various perspectives. They identified the areas where more concern is needed to reduce the disastrous impacts. This paper aims to find out the critical factors of human error in civil aviation in a developing country (Bangladesh) as it is accepted that human error is one of main causes of civil aviation disasters. The paper reviews the previous research to find out the critical factors conceptually. Fuzzy analytical hierarchy process (FAHP) has been used to find out the critical factors systematically. Analyses indicate that the concentration on precondition for unsafe acts (including sub-factors) is required to ensure the aviation safety.
Impact of exchange rate volatility has received a great attention from the last century, its importance is certain in all sectors of the economy and it affects welfare as well as social life of the economy. Exchange rate between two currencies tells the value of one currency in terms of others one. Depreciation/Appreciation of exchange rate affects economic growth in terms of trade and shifts income to/from exporting countries from/to importing countries. The factors affecting exchange rate are inflation, interest rate, foreign direct investment, government consumption expenditure and balance of trade. This research study examines the impact of oil prices and exchange rate volatility on economic growth in Germany based on 40-year annual data. Cointegration technique is applied to check the impact of macroeconomic variables on exchange rate in the long run and short run. It is estimated that imports, exports, inflation, interest rate, government consumption expenditure and foreign direct investment had significant impacts on real effective exchange rate in the long run and short run. Sin addition, Engle Granger results indicate that relationship was significant for the long run and its error correction adjustment mechanism (ECM) in short a run is significant and correctly signed for Germany.
Based on the Law and Finance theory, and the regulatory capture theory, external governance environment and industrial regulations can exert a certain influence on corporate over-investment. On the basis of qualitative analysis of the relationship between external governance environment and corporate over-investment under different industrial regulation conditions, this paper, using data of non-financial companies listed in Shanghai and Shenzhen Stock Exchanges in the period 2001-2010, describes the regional distribution characteristics of over-investment of Chinese listed companies, and establishes an OLS regression model of the relationship between external governance environment and over-investment. The study respectively groups data from regulated and non-regulated industries as a sample and empirically tests the OLS regression model. Results show that: from the perspective of economic geography, there exists a local spatial cluster phenomenon in the distribution of over-investment of listed companies in regulated industries, while non-regulated industries conform to no regularity. In regulated industries, external governance environment factors (level of government intervention, rule of law and financial development) may exert a significant negative influence on the degree of over-investment of listed companies, but on non-regulated industries, their effect is reversed. Also, government intervention, legal enforcement and financial development are positively correlated to over-investment. Further research indicates that, compared with government intervention and financial development, legal enforcement influences over-investment the most.
Based on studying organizational structure of Construction Green Supply Chain Management (CGSCM), a mathematical programming model of CGSCM was proposed. The model aimed to maximize the aggregate profits of normalized construction logistics, the reverse logistics and the environmental performance. Numerical experiments show that the proposed approach can improve the aggregate profit effectively. In addition, return ratio, subsidies from governmental organizations, and environmental performance were analyzed for CGSCM performance. Herein, the proper return, subsidy and control strategy could optimize construction green supply chain.
This paper studies the channel coordination between a supplier and a retailer with price and sales effort dependent demand. By means of game theory, we analyze price and sales effort decisions of the centralized supply chain. Then we consider three different contracts under decentralized model, i.e., wholesale price contract, cost-sharing contract and a two-part tariff contract, in which the supplier offers a contract comprising a wholesale price and a lump-sum fee to the retailer to coordinate the supply chain. Finally, we analyze the results to compare the equilibrium decisions under different contract scenarios. Our results show that both the wholesale price contract and the cost-sharing contract cannot coordinate the supply chain while the two-part tariff contract can effectively coordinate the supply chain.